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Full vulnerability report · 2021
CVE-2021-40358High confidence

Siemens SIMATIC PCS 7 V8.2 — Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Siemens · SIMATIC PCS 7 V8.2

9.9CriticalCVSS 3.1
Recommended action
Within 7 days

Critical technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
SSA-840188 · CSAF 2.0 · revision 7 · finalSiemens ProductCERTSSA-840188: Multiple Vulnerabilities in SIMATIC WinCC Affecting Other SIMATIC Software Products
8 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • SIMATIC PCS 7 V8.2
  • SIMATIC PCS 7 V9.0
  • SIMATIC PCS 7 V9.1
  • SIMATIC WinCC V15 and earlier
  • SIMATIC WinCC V16
  • SIMATIC WinCC V17
  • SIMATIC WinCC V7.4
  • SIMATIC WinCC V7.5
Summary
Legitimate file operations on the web server of the affected systems do not properly neutralize special elements within the pathname. An attacker could then cause the pathname to resolve to a location outside of the restricted directory on the server and read, write or delete unexpected critical files.
Remediation
Update to V8.2 SP1; then update SIMATIC WinCC to V7.4 SP1 Update 19 or later version to fix CVE-2021-40358 and CVE-2021-40364
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2021-27536

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

Critical technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

A vulnerability has been identified in SIMATIC PCS 7 V8.2 (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP3 UC04), SIMATIC PCS 7 V9.1 (All versions < V9.1 SP1), SIMATIC WinCC V15 and earlier (All versions < V15 SP1 Update 7), SIMATIC WinCC V16 (All versions < V16 Update 5), SIMATIC WinCC V17 (All versions < V17 Update 2), SIMATIC WinCC V7.4 (All versions < V7.4 SP1 Update 19), SIMATIC WinCC V7.5 (All versions < V7.5 SP2 Update 5). Legitimate file operations on the web server of the affected systems do not properly neutralize special elements within the pathname. An attacker could then cause the pathname to resolve to a location outside of the restricted directory on the server and read, write or delete unexpected critical files.

What

A vulnerability has been identified in SIMATIC PCS 7 V8.2 (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP3 UC04), SIMATIC PCS 7 V9.1 (All versions < V9.1 SP1), SIMATIC WinCC V15 and earlier (All versions < V15 SP1 Update 7), SIMATIC WinCC V16 (All versions < V16 Update 5), SIMATIC WinCC V17 (All versions < V17 Update 2), SIMATIC WinCC V7.4 (All versions < V7.4 SP1 Update 19), SIMATIC WinCC V7.5 (All versions < V7.5 SP2 Update 5). Legitimate file operations on the web server of the affected systems do not properly neutralize special elements within the pathname. An attacker could then cause the pathname to resolve to a location outside of the restricted directory on the server and read, write or delete unexpected critical files.

Why

Attacker-controlled path data is not constrained to the intended directory before the application accesses a file.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

A vulnerability has been identified in SIMATIC PCS 7 V8.2 (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP3 UC04), SIMATIC PCS 7 V9.1 (All versions < V9.1 SP1), SIMATIC WinCC V15 and earlier (All versions < V15 SP1 Update 7), SIMATIC WinCC V16 (All versions < V16 Update 5), SIMATIC WinCC V17 (All versions < V17 Update 2), SIMATIC WinCC V7.4 (All versions < V7.4 SP1 Update 19), SIMATIC WinCC V7.5 (All versions < V7.5 SP2 Update 5). Legitimate file operations on the web server of the affected systems do not properly neutralize special elements within the pathname. An attacker could then cause the pathname to resolve to a location outside of the restricted directory on the server and read, write or delete unexpected critical files.

Why

Attacker-controlled path data is not constrained to the intended directory before the application accesses a file.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Changed: exploitation can affect a different security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-22 ↗

CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'). The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SChangedScope: The attack can affect a component governed by a different security authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkCWE-22
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

Cyber Security Agency of Singapore · English · CSA-SB-20211110Security Bulletin 10 Nov 2021

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 10 Nov 2021, published on 10 November 2021. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-124Multiples vulnérabilités dans les produits Siemens

d?id=CVE-2021-37186 Référence CVE CVE-2021-37194 https://www.cve.org/CVERecord?id=CVE-2021-37194 Référence CVE CVE-2021-37195 https://www.cve.org/CVERecord?id=CVE-2021-37195 Référence CVE CVE-2021-37196 https://www.cve.org/CVERecord?id=CVE-2021-37196 Référence CVE CVE-2021-37197 https://www.cve.org/CVERecord?id=CVE-2021-37197 Référence CVE CVE-2021-37198 https://www.cve.org/CVERecord?id=CVE-2021-37198 Référence CVE CVE-2021-37204 https://www.cve.org/CVERecord?id=CVE-2021-37204 Référence CVE CVE-2021-37205 https://www.cve.org/CVERecord?id=CVE-2021-37205 Référence CVE CVE-2021-38405 https://www.cve.org/CVERecord?id=CVE-2021-38405 Référence CVE CVE-2021-40358 https://www.cve.org/CVERecord?id=CVE-2021-40358 Référence CVE CVE-2021-40359 https://www.cve.org/CVERecord?id=CVE-2021-40359 Référence CVE CVE-2021-40360 https://www.cve.org/CVERecord?id=CVE-2021-40360 Référence CVE CVE-2021-40363 https://www.cve.org/CVERecord?id=CVE-2021-40363 Référence CVE CVE-2021-40364 https://www.cve.org/CVERecord?id=CVE-2021-40364 Référence CVE CVE-2021-41990 https://www.cve.org/CVERecord?id=CVE-2021-41990 Référence CVE CVE-2021-41991 https://www.cve.org/CVERecord?id=CVE-2021-41991 Référence CVE CVE-2021-43336 https://www.cve.org/CVERecord?id=CVE-2021-43336 Référence CVE CVE-2021-44000 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-854Multiples vulnérabilités dans les produits Siemens

d?id=CVE-2021-31889 Référence CVE CVE-2021-31890 https://www.cve.org/CVERecord?id=CVE-2021-31890 Référence CVE CVE-2021-37207 https://www.cve.org/CVERecord?id=CVE-2021-37207 Référence CVE CVE-2021-37726 https://www.cve.org/CVERecord?id=CVE-2021-37726 Référence CVE CVE-2021-37727 https://www.cve.org/CVERecord?id=CVE-2021-37727 Référence CVE CVE-2021-37730 https://www.cve.org/CVERecord?id=CVE-2021-37730 Référence CVE CVE-2021-37732 https://www.cve.org/CVERecord?id=CVE-2021-37732 Référence CVE CVE-2021-37734 https://www.cve.org/CVERecord?id=CVE-2021-37734 Référence CVE CVE-2021-37735 https://www.cve.org/CVERecord?id=CVE-2021-37735 Référence CVE CVE-2021-40358 https://www.cve.org/CVERecord?id=CVE-2021-40358 Référence CVE CVE-2021-40359 https://www.cve.org/CVERecord?id=CVE-2021-40359 Référence CVE CVE-2021-40364 https://www.cve.org/CVERecord?id=CVE-2021-40364 Référence CVE CVE-2021-40366 https://www.cve.org/CVERecord?id=CVE-2021-40366 Référence CVE CVE-2021-41057 https://www.cve.org/CVERecord?id=CVE-2021-41057 Référence CVE CVE-2021-41533 https://www.cve.org/CVERecord?id=CVE-2021-41533 Référence CVE CVE-2021-41534 https://www.cve.org/CVERecord?id=CVE-2021-41534 Référence CVE CVE-2021-41535 https://www.cve.org/CVERecord?id=CVE-2021-41535 Référence CVE CVE-2021-41538 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2021-014830SIMATIC PCS 7 および SIMATIC WinCC におけるパストラバーサルの脆弱性

SIMATIC PCS 7 および SIMATIC WinCC には、パストラバーサルの脆弱性が存在します。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
Update to V8.2 SP1; then update SIMATIC WinCC to V7.4 SP1 Update 19 or later version to fix CVE-2021-40358 and CVE-2021-40364
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 9 Nov 2021 · Last source change 4 Aug 2024, 02:44 UTC · CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVE recordCVE.org · 5.1
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2021-27536
Product sourceVendor CSAF · Siemens ProductCERT
Remediation sourceVendor CSAF · Siemens ProductCERT
CWE sourceCNA
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2021-27536↗Vendor CSAF · Siemens ProductCERT↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2021-40358 · cve.blacktree.nl